Compressor

ABSTRACT

A compressor is provided with a cylinder block including a cylinder bore, a housing coupled to the end of the cylinder block, and a discharge valve held between the cylinder block and the housing. An end of the cylinder block includes a partition that closes one end of the cylinder bore. The partition includes a bottom portion forming a bottom surface of the cylinder bore. The housing includes an outer wall and an inner wall. The outer wall includes two partition supports that are in contact with parts of the bottom portion. The two partition supports are arranged on opposite sides of the discharge valve and extend toward the inner wall.

BACKGROUND OF THE INVENTION

The present invention relates to a compressor, and more particularly to a compressor including a cylinder block and a housing.

Japanese Laid-Open Patent Publication No. 8-121330 describes a reciprocating compressor including single-headed pistons. The compressor includes a cylinder block having six bores. Each of the portions that respectively defines the bore has a bottom portion forming a valve seat. The valve seat includes a discharge port. The bores form chambers that are completely independent from one another. A rear housing is coupled to a rear end of the cylinder block. A suction chamber is formed in a central portion of the rear housing and opens toward a rear end of the rear housing. A discharge chamber is formed at the radially outer side of the suction chamber. A discharge valve and a retainer are arranged in the discharge port near the discharge chamber. The cylinder block is coupled with the rear housing to hold the discharge valve and the retainer.

When a piston compresses refrigerant in a corresponding one of the bores, the pressure of the bore becomes high and deforms the valve seat (also referred to as the partition). As a result, stress may concentrate at edges in the bore and damage the partition. In the compressor of the above publication, the discharge chamber has a thick outer wall that supports the partition from the rear. This suppresses deformation of the partition. However, the formation of the thick outer wall in the rear housing decreases the volume of the discharge chamber. This may increase noise by a certain amount when refrigerant is discharged. Further, the thick outer wall decreases the length of the discharge valve arranged near the discharge chamber in the corresponding discharge chamber. As a result, the discharge valve becomes less flexible. This may adversely affect the moving characteristics of the discharge valve.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compressor that suppresses deformation of the partition without adversely affecting the moving characteristics of the discharge valve.

One aspect of the present invention is a compressor provided with a cylinder block including a cylinder bore. The cylinder block includes an end. The end of the cylinder block includes a partition that closes one end of the cylinder bore. The partition includes a bottom portion forming a bottom surface of the cylinder bore. The bottom portion includes a discharge port, and the discharge port extends through the bottom portion and is in communication with the cylinder bore. A housing is coupled to the end of the cylinder block. The housing includes an annular outer wall, an annular inner wall located at an inner side of the outer wall, a discharge chamber formed between the outer wall and the inner wall, and a suction chamber formed at an inner side of the inner wall. A discharge valve is held between the cylinder block and the housing. The outer wall includes two partition supports that are in contact with parts of the bottom portion. The two partition supports are arranged on opposite sides of the discharge valve and extend toward the inner wall.

Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

FIG. 1 is a cross-sectional view entirely showing a compressor according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1;

FIG. 4 is a plan view of a discharge valve of a discharge valve shown in FIG. 1;

FIG. 5 is a rear view of a front housing in the compressor shown in FIG. 1;

FIG. 6 is a cross-sectional view taken along line C-C in FIG. 5;

FIG. 7 is a cross-sectional view taken along line D-D in FIG. 1;

FIG. 8 is a cross-sectional view taken along line E-E in FIG. 1;

FIG. 9 is a front view of a rear housing in the compressor shown in FIG. 1;

FIG. 10 is a front view of a rear housing in a compressor according to a second embodiment of the present invention;

FIG. 11 is a cross-sectional view taken along line F-F in FIG. 10;

FIG. 12 is a rear view of a front housing in a compressor according to a third embodiment of the present invention;

FIG. 13 is a cross-sectional view taken along line G-G in FIG. 12; and

FIG. 14 is a front view of a rear housing shown in FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

A first embodiment of a compressor will now be described with reference to FIGS. 1 to 9. FIG. 1 shows a compressor 10 that is a double-headed piston swash plate compressor. In the present embodiment, a housing of the compressor 10 includes two coupled cylinder blocks 11 and 12, a front housing 13 coupled to the cylinder block 11, and a rear housing 14 coupled to the cylinder block 12. Bolts 56 integrally fasten the front housing 13, the cylinder blocks 11 and 12, and the rear housing 14.

A shaft hole 11A extends through the cylinder block 11, and a shaft hole 12A extends through the cylinder block 12. A rotation shaft 15 is inserted into the shaft holes 11A and 12A and supported to be rotatable by a sealed surface of the wall of the shaft holes 11A and 12A. The rotation shaft 15 includes a front projecting end where a lip seal type sealing device 16 is arranged between the rotation shaft 15 and an inner wall of the front housing 13. The sealing device 16 is accommodated in an accommodation chamber 13A defined between the rotation shaft 15 and the inner wall of the front housing 13.

A swash plate 17, which rotates integrally with the rotation shaft 15, is fixed to the rotation shaft 15. A swash plate chamber 18 is formed in the cylinder blocks 11 and 12. The swash plate 17 is accommodated in the swash plate chamber 18. The swash plate 17 includes an annular base 17A. A thrust bearing 19 is arranged between one end of the front cylinder block 11 and the base 17A of the swash plate 17. A thrust bearing 20 is arranged between the other end of the rear cylinder block 12 and the base 17A of the swash plate 17. The thrust bearings 19 and 20 sandwich the swash plate 17 and restrict movement of the swash plate 17 in the direction of the axis L of the rotation shaft 15. Further, the thrust bearings 19 and 20 are pressed against the open ends of the shaft holes 11A and 12A in the cylinder blocks 11 and 12.

Referring to FIG. 2, the front cylinder block 11 includes three front cylinder bores 21 arranged around the rotation shaft 15. Further, referring to FIG. 7, in the same manner as the front cylinder block 11, the rear cylinder block 12 includes three rear cylinder bores 22 arranged around the rotation shaft 15. The front cylinder bores 21 are paired and aligned with the rear cylinder bores 22 in the direction of the axis L. A double-headed piston 23 is inserted into each pair of the aligned cylinder bores 22. The front end of the cylinder block 11 includes a partition 11B that closes one end of each of the front cylinder bores 21. The partition 11B is formed integrally with the cylinder block 11. The partition 11B includes a bottom portion 11C forming a bottom surface of each front cylinder bore 21. The rear end of the cylinder block 12 includes a partition 12B that closes one end of each of the rear cylinder bores 22. The partition 12B is formed integrally with the cylinder block 12. The partition 12B includes a bottom portion 12C forming a bottom surface of each rear cylinder bore 22.

In each double-headed piston 23, two shoes 24 sandwich the swash plate 17 and transmit the rotating motion of the swash plate 17, which is rotated integrally with the rotation shaft 15, to the double-headed piston 23. This reciprocates the double-headed piston 23 in the corresponding front cylinder bore 21 and rear cylinder bore 22. A front compression chamber 25 is defined in the front cylinder bore 21 between the double-headed piston 23 and the bottom portion 11C. A rear compression chamber 26 is defined in the rear cylinder bore 22 between the double-headed piston 23 and the bottom portion 12C.

Referring to FIG. 2, the cylinder block 11 includes three cylinder block suction chambers 27 arranged around the shaft hole 11A. Each cylinder block suction chamber 27 is arranged between the front cylinder bores 21 that are adjacent to each other in the circumferential direction around the shaft hole 11A. The cylinder block suction chambers 27 are arranged at equal intervals around the shaft hole 11A. Further, the cylinder block 11 includes three cylinder block discharge chambers 29 arranged around the shaft hole 11A. Each cylinder block discharge chamber 29 is arranged between the front cylinder bores 21 that are adjacent to each other in the circumferential direction around the shaft hole 11A. The cylinder block discharge chambers 29 are arranged at equal intervals around the shaft hole 11A. Further, the cylinder block discharge chambers 29 are located at the outer sides of the cylinder block suction chambers 27 in the radial direction of the cylinder block 11.

Referring to FIGS. 1 and 3, three discharge ports 30 extend through the bottom portion 11C of the cylinder block 11 to communicate the front cylinder bores 21 with front discharge chambers 28. A discharge valve 31 is arranged at the discharge ports 30 near the front discharge chambers 28 so as to cover the discharge ports 30. As shown in FIG. 4, the discharge valve 31 includes fixed portions 31A, which are held between an inner wall 34 and the partition 11B, and valve portions 31B, which extend from the fixed portions 31A toward an outer wall 33. A gasket 32 is formed integrally with a retainer 32A, which restricts the opening angle of the discharge valve 31.

Referring to FIGS. 3 and 5, the front housing 13 includes the outer wall 33 and the inner wall 34, which is located at the inner side of the outer wall 33. Each of the outer wall 33 and the inner wall 34 are annular. The front discharge chambers 28 are formed between the outer wall 33 and the inner wall 34, and front suction chambers 55 are formed at the inner side of the inner wall 34. The front suction chambers 55 are in communication with the accommodation chamber 13A.

The outer wall 33 isolates the front discharge chambers 28, which are formed at the inner side of the outer wall 33, from the exterior and has a predetermined thickness in the radial direction. The outer wall 33 includes a plurality of partition supports 33A that extend toward the inner wall 34. The partition supports 33A are in contact with parts of the bottom portions 11C. The distal end of each valve portion 31B is arranged between two of the partition supports 33A. As shown by the broken lines in FIG. 5, in the prior art, to decrease weight, the outer wall 33 is shaped to have a predetermined thickness in the radial direction, while extending toward the inner side at portions that receive the bolts 56. In the present embodiment, however, to increase the strength of the bottom portion 11C, the outer wall 33 includes multiple pairs of the partition supports 33A that come into contact with the bottom portion 11C. The partition supports 33A in each pair are arranged on opposite sides of the distal end of the corresponding valve portion 31B and extend toward the inner wall 34.

The inner wall 34 isolates the front discharge chambers 28, which are formed at the outer side of the inner wall 34, from the front suction chambers 55, which are formed at the inner side of the inner wall 34. Parts of the inner wall 34 form valve supports 34A. The fixed portions 31A are held between the valve supports 34A and the bottom portion 11C with the valve supports 34A partially covering parts of the bottom portion 11C.

As shown in FIGS. 5 and 6, ribs 35 connect the inner wall 34 and the outer wall 33. The ribs 35 are opposed to the bottom portion 11C. Further, the ribs 35 connect the valve supports 34A of the inner wall 34 with portions of the outer wall 33 located between the two partition supports 33A of each pair. The longitudinal direction of the ribs 35 conforms to the radial direction of the compressor. The ribs 35 each have a height T2 in the direction of axis L. The inner wall 34 and the outer wall 33 each have a height T1 in the direction of axis L. The height T2 of the ribs 35 is set to be lower than the height T1 of the inner wall 34 and the outer wall 33. Thus, when the discharge valve 31 and the gasket 32 are held between the cylinder block 11 and the front housing 13, the ribs 35 do not contact the discharge valves 31 and the gasket 32.

As shown in FIGS. 1 and 3, the cylinder block 11 and the front housing 13 are coupled to each other with the discharge valve 31 and the gasket 32 arranged in between. Through holes extend through the discharge valve 31 and the gasket 32 to communicate the cylinder block discharge chambers 29, which are formed in the cylinder block 11, with the front discharge chambers 28, which are formed in the front housing 13. Further, through holes extend through the discharge valve 31 and the gasket 32 to communicate the front suction chambers 55, which are formed in the front housing 13, with the front suction chambers 55, which are formed in the front housing 13. In the front housing 13, the coupling of the cylinder block 11 and the front housing 13 with the discharge valve 31 and the gasket 32 arranged in between forms the front suction chambers 55, which are in communication with the cylinder block suction chambers 27 and isolated from the exterior, and the front discharge chambers 28, which are in communication with the cylinder block suction chambers 27 and isolated from the exterior.

The rear structure of the compressor 10 will now be described. Referring to FIG. 7, the cylinder block 12 includes three cylinder block suction chambers 36 arranged around the shaft hole 12A. Each cylinder block suction chamber 36 is arranged between the rear cylinder bores 22 that are adjacent to each other in the circumferential direction around the shaft hole 12A. The cylinder block suction chambers 36 are arranged at equal intervals around the shaft hole 12A. Further, the cylinder block 12 includes three cylinder block discharge chambers 45 arranged around the shaft hole 12A. Each cylinder block discharge chamber 45 is arranged between the rear cylinder bores 22 that are adjacent to each other in the circumferential direction around the shaft hole 12A. The cylinder block discharge chambers 45 are arranged at equal intervals around the shaft hole 12A. Further, the cylinder block discharge chambers 45 are located at the outer sides of the cylinder block suction chambers 36 in the radial direction of the cylinder block 12. The cylinder block suction chambers 27 are paired and aligned with the cylinder block suction chambers 36 in the direction in which the axis L extends.

Referring to FIGS. 1 and 8, three discharge ports 39 extend through the bottom portion 12C of the cylinder block 12 to communicate the rear cylinder bores 22 with rear discharge chambers 38. A discharge valve 40 is arranged at the discharge ports 39 near the rear discharge chambers 38 so as to cover the discharge ports 39. The discharge valve 40 includes fixed portions 40A, which are held between an inner wall 43 and the partition 12B, and valve portions 40B, which extend from the fixed portions 40A toward an outer wall 42. A gasket 41 is formed integrally with a retainer 41A, which restricts the opening angle of the discharge valve 40.

Referring to FIGS. 8 and 9, the front housing 13 includes the outer wall 42 and the inner wall 43, which is located at the inner side of the outer wall 42. Each of the outer wall 42 and the inner wall 43 are annular. The rear discharge chambers 38 are formed between the outer wall 42 and the inner wall 43, and rear suction chambers 57 are formed at the inner side of the inner wall 43. The rear suction chambers 57 are in communication with a suction chamber 37 located at the inner side of the rear suction chambers 57.

The outer wall 42 isolates the rear discharge chambers 38, which are formed at the inner side of the outer wall 42, from the exterior and has a predetermined thickness in the radial direction. In the same manner as the front side, the outer wall 42 includes a plurality of partition supports 42A that extend toward the inner wall 43. The partition supports 42A are in contact with parts of the bottom portions 12C. The distal end of each valve portion 40B is arranged between two of the partition supports 42A. The partition supports 42A in each pair are arranged on opposite sides of the distal end of the corresponding valve portion 40B and extend toward the inner wall 43.

The inner wall 43 isolates the rear discharge chambers 38, which are formed at the outer side of the inner wall 43, from the rear suction chambers 57, which are formed at the inner side of the inner wall 43. Parts of the inner wall 43 form valve supports 43A. The fixed portions 40A are held between the valve supports 43A and the bottom portion 12C with the valve supports 43A partially covering the bottom portion 12C. That is, the valve supports 43A contact the fixed portions 40A and force the fixed portions 40A against parts of the bottom portion 12C.

As shown in FIG. 9, ribs 44 connect the inner wall 43 and the outer wall 42. The ribs 44 are opposed to the bottom portion 12C. Further, the ribs 44 connect the valve supports 43A of the inner wall 43 with portions of the outer wall 42 located between the two partition supports 42A of each pair. The longitudinal direction of the ribs 44 conforms to the radial direction of the compressor. The height of the ribs 44 in the direction of axis L is lower than the height of the inner wall 43 and the outer wall 42 in the direction of axis L. Thus, when the discharge valve 40 and the gasket 41 are held between the cylinder block 12 and the rear housing 14, the ribs 44 do not contact the discharge valves 40 and the gasket 41.

As shown in FIG. 1, the cylinder block 12 and the rear housing 14 are coupled to each other with the discharge valve 40 and the gasket 41 arranged in between. Through holes extend through the discharge valve 40 and the gasket 41 to communicate the cylinder block discharge chambers 45, which are formed in the cylinder block 12, with the rear discharge chambers 38, which are formed in the rear housing 14. Further, through holes extend through the discharge valve 40 and the gasket 41 to communicate the cylinder block suction chambers 36, which are formed in the cylinder block 12, with the rear suction chambers 57, which are formed in the rear housing 14. In the rear housing 14, the coupling of the cylinder block 12 and the rear housing 14 with the discharge valve 40 and the gasket 41 arranged in between forms the rear suction chambers 57 and 37, which are in communication with the cylinder block suction chambers 36 and isolated from the exterior, and the rear discharge chambers 38, which are in communication with the cylinder block discharge chambers 45 and isolated from the exterior.

As shown in FIG. 1, a suction passage 46 extends through the cylinder blocks 11 and 12. The suction passage 46 has a front opening that is in communication with one of the three cylinder block suction chambers 27 and a rear opening that is in communication with one of the three cylinder block suction chambers 36. Further, the front cylinder block 11 includes an inlet 47. The inlet 47 has one end, which opens in the outer surface of the cylinder block 11, and another end, which opens in the wall surface of the suction passage 46. A pipe connects the inlet 47 to an external refrigerant circuit.

A discharge passage 48 (refer to FIG. 2) extends through the cylinder blocks 11 and 12. The discharge passage 48 has a front opening that is in communication with one of the three cylinder block discharge chambers 29 and a rear opening that is in communication with one of the three cylinder block discharge chambers 45. Further, the front cylinder block 11 includes an outlet (not shown). The outlet has one end, which opens in the outer surface of the cylinder block 11, and another end, which opens in the wall surface of the discharge passage 48. A pipe connects the outlet to the external refrigerant circuit. As shown in FIG. 2, the discharge passage 48 is separated from the suction passage 46 in the circumferential direction of the cylinder block.

The front suction structure will now be described. As shown in FIG. 2, the cylinder block 11 includes suction chamber communication passages 50 that communicate the cylinder block suction chambers 27 and the shaft hole 11A. Further, the cylinder block 11 includes bore communication passages 51 that communicate the shaft hole 11A and the front cylinder bores 21. The suction chamber communication passages 50 and the bore communication passages 51 are alternately arranged in the circumferential direction around the shaft hole 11A.

As shown in FIGS. 1 and 2, a front portion of the rotation shaft 15 includes an intake groove 52 formed in the circumferential surface. The intake groove 52 opens toward the sealed surface of the shaft hole 11A and is separately communicable with the suction chamber communication passages 50 and the bore communication passages 51. The rotation of the rotation shaft 15 moves the intake groove 52 and mechanically switches the suction chamber communication passages 50 and the bore communication passages 51 that are in communication with the intake groove 52. In this manner, the portion of the rotation shaft 15 enclosed by the sealed surface functions as a front rotary valve formed integrally with the rotation shaft 15.

The rear suction structure will now be described. As shown in FIGS. 1 and 7, the cylinder block 12 includes rear intake passages 53 that communicate the rear cylinder bores 22 and the shaft hole 12A. Further, a rear portion of the rotation shaft 15 includes a supply groove 54 formed in the circumferential surface. The supply groove 54 has one end that opens toward the suction chamber 37 in the rear housing 14 and another end that is communicable with the rear intake passages 53. The rotation of the rotation shaft 15 moves the supply groove 54 and mechanically switches the rear intake passages 53 that are in communication with the supply groove 54. In this manner, the portion of the rotation shaft 15 enclosed by the sealed surface functions as a rear rotary valve formed integrally with the rotation shaft 15.

The operation of the compressor 10 will now be described. Refrigerant is drawn through the inlet 47 into the suction passage 46 and supplied to each of the cylinder block suction chambers 27 and 36. Referring to FIG. 2, when a front cylinder bore 21 enters a suction stroke, the intake groove 52 of the front rotary valve communicates the corresponding bore communication passage 51 with an adjacent one of the suction chamber communication passage 50. This draws refrigerant into the front cylinder bore 21 from the corresponding cylinder block suction chamber 27 through the front rotary valve.

Further rotation of the rotation shaft 15 moves the intake groove 52 and separates the bore communication passage 51 from the suction chamber communication passage 50. This closes the front cylinder bore 21, and the front cylinder bore 21 shifts to the compression stroke and the discharge stroke. More specifically, the refrigerant drawn into the corresponding front compression chamber 25 is compressed to a high pressure as the corresponding double-headed piston 23 moves toward the front. Then, the refrigerant forcibly opens the discharge valve 31 from the discharge port 30 and is discharged into the corresponding front discharge chamber 28. Here, the pressure of the refrigerant discharged from the discharge port 30 moves the valve portion 31B of the discharge valve 31 to a position where the valve portion 31B contacts the retainer 32A of the gasket 32 to open the discharge valve 31.

In the compression stroke, the pressure of the refrigerant in the front compression chamber 25 is high. Thus, an external force resulting from the internal pressure pushing the bottom portion 11C toward the front acts on and deforms the bottom portion 11C. When the bottom portion 11C is deformed, stress is concentrated at an edge R, which is where the bottom portion 11C and the front cylinder bore 21 are connected. The front housing 13 includes the outer wall 33 and the inner wall 34 that define the front discharge chambers 28 and the front suction chambers 55. The partition 11B of the cylinder block 11 applies force through at least one of the discharge valve 31 and the gasket 32 to the end surface of the outer wall 33 and the end surface of the inner wall 34.

The partition supports 33A extend from the outer wall 33 and are in contact with parts of the bottom portion 11C. In the present embodiment, the partition supports 33A are in contact with parts of the bottom portion 11C through the gasket 32. Thus, the area in which the front housing 13 contacts the bottom portion 11C is increased in comparison with the prior art. This suppresses deformation of the bottom portion 11C during compression. Further, the partition supports 33A are arranged in pair on opposite sides of the distal ends of the valve portions 31B. This prevents interference between the discharge valve 31 and the partition supports 33A, while maintaining a predetermined length in the radial direction for the discharge valve 31 (length from the fixed portions 31A to the valve portions 31B).

Further, the fixed portions 31A are held between the valve supports 34A, which are portions of the inner wall 34, and the bottom portion 11C with the valve supports 34A partially covering the bottom portion 11C. Thus, the area in which the front housing 13 contacts the bottom portion 11C is increased in comparison with the prior art. This further suppresses deformation of the bottom portion 11C during compression. The valve supports 34A function to hold the fixed portions 31A of the discharge valve 31 and function to suppress deformation of the bottom portion 11C.

The ribs 35 connect the inner wall 34 and the outer wall 33 and are opposed to the bottom portion 11C. This improves the strength of the inner wall 34 and the outer wall 33, improves the rigidity of the entire front housing 13, and further suppresses deformation of the bottom portion 11C during compression. Further, the height T2 of the ribs 35 in the direction of the axis L is set to be lower than the height T1 of the inner wall 34 and the outer wall 33 in the direction of the axis L. Thus, the ribs 35 do not interfere with the discharge valve 31 and the gasket 32, and the moving characteristics of the discharge valve 31 are unaffected.

The formation of the partition supports 33A and the valve supports 34A decreases the volume of the front discharge chambers 28. However, in contrast with when entirely increasing the thickness of the outer wall 33 or the inner wall 34, sufficient volume is ensured for the front discharge chambers 28. This obviates the generation of noise when refrigerant is discharged. The refrigerant discharged to the front discharge chambers 28 flows through the cylinder block discharge chambers 29 and enters the external refrigerant circuit via the discharge passage 48 and the outlet.

At the rear side of the compressor, when refrigerant is drawn into the suction chamber 37, if a rear cylinder bore 22 enters a suction stroke, the supply groove 54 of the rear rotary valve, which is in communication with the suction chamber 37, comes into communication with the corresponding rear intake passage 53. This draws refrigerant from the suction chamber 37 through the rear rotary valve and into the rear intake passage 53. The refrigerant is further drawn into the cylinder bore 22 that is in communication with the rear intake passage 53.

Further rotation of the rotation shaft 15 separates the supply groove 54 from the rear intake passage 53 and closes the rear cylinder bore 22. Then, the rear cylinder bore 22 shifts to the compression stroke and the discharge stroke. More specifically, the refrigerant drawn into the corresponding rear compression chamber 26 is compressed to a high pressure as the corresponding double-headed piston 23 moves toward the rear. Then, the refrigerant forcibly opens the discharge valve 40 from the discharge port 39 and is discharged into the corresponding rear discharge chamber 38. Here, the pressure of the refrigerant discharged from the discharge port 39 moves the valve portion 40B of the discharge valve 40 to a position where the valve portion 40B contacts the retainer 41A of the gasket 41 to open the discharge valve 40.

In the compression stroke, the pressure of the refrigerant in the rear compression chamber 26 is high. Thus, an external force acts on and deforms the bottom portion 12C. When the bottom portion 12C is deformed, stress is concentrated at an edge R, which is where the bottom portion 12C and the rear cylinder bore 22 are connected. In the same manner as the front housing 13, the rear housing 14 includes the outer wall 42 and the inner wall 43 that define the rear discharge chambers 38 and the rear suction chambers 57. The partition 12B of the cylinder block 12 applies force through at least one of the discharge valve 40 and the gasket 41 to the end surface of the outer wall 42 and the end surface of the inner wall 43.

The partition supports 42A extend from the outer wall 42, the inner wall 43 includes the valve supports 43A, and the ribs 44 connect the inner wall 43 and the outer wall 42. This structure is the same as the front side and obtains the same advantages as the front side. The outer wall 33, the inner wall 34, the partition supports 33A, the valve supports 34A, the ribs 35, the front suction chambers 55, and the front discharge chambers 28 at the front side correspond to the outer wall 42, the inner wall 43, the partition supports 42A, the valve supports 43A, the ribs 44, the rear suction chambers 57, and the rear discharge chambers 38 at the rear side. The refrigerant discharged to the rear discharge chambers 38 flows through the cylinder block discharge chambers 45 and enters the external refrigerant circuit via the discharge passage 48 and the outlet.

The compressor 10 of the first embodiment has the advantages described below.

(1) The partition supports 33A extend from the outer wall 33 of the front housing 13, and the partition supports 33A contact parts of the bottom portion 11C. This increases the area in which the front housing 13 contacts the bottom portion 11C and allows for deformation of the bottom portion 11C to be suppressed during compression. Further, the partition supports 33A are arranged in pairs so that the partition supports 33A of each pair are arranged on opposite sides of the distal end of the corresponding valve portion 31B. This prevents interference between the discharge valve 31 and the partition supports 33A, maintains the length of the discharge valve 31 (length from fixed portion 31A to valve portion 31B) at a predetermined length, and allows for deterioration of the moving characteristics of the discharge valve 31 to be obviated.

(2) The valve supports 34A are formed by portions of the inner wall 34 in the front housing 13, and the fixed portions 31A are held between the valve supports 34A and the bottom portion 11C with the valve supports 34A partially covering parts of the bottom portion 11C. This increases the area in which the front housing 13 contacts the bottom portion 11C and allows for deformation of the bottom portion 11C to be further suppressed during compression. Further, the valve supports 34A function to hold the fixed portions 31A of the discharge valve 31 and function to suppress deformation of the bottom portion 11C. This simplifies the structure.

(3) The ribs 35 connect the inner wall 34 and the outer wall 33 in the front housing 13, and the ribs 35 are opposed to the bottom portion 11C. This improves the rigidity of the inner wall 34 and the outer wall 33, and allows for deformation of the bottom portion 11C to be further suppressed during compression. Further, the height T2 of the ribs 35 in the direction of the axis L is set to be lower than the height T1 of the inner wall 34 and the outer wall 33 in the direction of the axis L. Thus, the ribs 35, the discharge valve 31, and the gasket 32 do not interfere with one another, and the moving characteristics of the discharge valve 31 are unaffected.

(4) The formation of the partition supports 33A and the valve supports 34A in the front housing 13 decreases the volume of the front discharge chambers 28. However, in contrast with when entirely increasing the thickness of the outer wall 33 or the inner wall 34, sufficient volume is ensured for the front discharge chambers 28. This obviates the generation of noise when refrigerant is discharged.

(5) The partition supports 42A extend from the outer wall 42 of the rear housing 14, and the partition supports 42A contact parts of the bottom portion 12C. As a result, the area in which the rear housing 14 contacts the bottom portion 12C is increased, and deformation of the bottom portion 12C is suppressed during compression. Further, the partition supports 42A are arranged in pairs so that the partition supports 42A of each pair are arranged on opposite sides of the distal end of the corresponding valve portion 40B. This prevents interference between the discharge valve 40 and the partition supports 42A, maintains the length of the discharge valve 40 (length from fixed portion 40A to valve portion 40B) at a predetermined length, and allows for deterioration of the moving characteristics of the discharge valve 40 to be obviated.

(6) The inner wall 43 of the rear housing 14 includes the valve supports 43A, and the fixed portions 40A are held between the valve supports 43A and the bottom portion 12C with the valve supports 43A partially covering parts of the bottom portion 12C. This increases the area in which the rear housing 14 contacts the bottom portion 12C and allows for deformation of the bottom portion 12C to be further suppressed during compression. Further, the valve supports 43A function to hold the fixed portions 40A of the discharge valve 40 and function to suppress deformation of the bottom portion 12C. This simplifies the structure.

(7) The ribs 44 connect the inner wall 43 and the outer wall 42 in the rear housing 14, and the ribs 44 are opposed to the bottom portion 12C. The ribs 44 improve the rigidity of the inner wall 43 and the outer wall 42, and allows for deformation of the bottom portion 12C to be further suppressed during compression. Further, the height of the ribs 44 in the direction of the axis L is set to be lower than the height of the inner wall 43 and the outer wall 42 in the direction of the axis L. Thus, the ribs 44, the discharge valve 40, and the gasket 41 do not interfere with one another, and the moving characteristics of the discharge valve 40 are unaffected.

(8) The formation of the partition supports 42A and the valve supports 43A in the rear housing 14 decreases the volume of the rear discharge chambers 38. However, in contrast with when entirely increasing the thickness of the outer wall 42 or the inner wall 43, sufficient volume is ensured for the rear discharge chambers 38. This obviates the generation of noise when refrigerant is discharged.

Second Embodiment

A second embodiment of a compressor will now be described with reference to FIGS. 10 and 11. In this embodiment, the shape of the rear housing 14 is changed from the first embodiment. Otherwise, the structure of the second embodiment is the same as the first embodiment. Like or same reference numerals are given to those components that are the same as the corresponding components of the first embodiment. Such components will not be described in detail.

As shown in FIGS. 10 and 11, in the present embodiment, a rear housing 61 includes cylindrical projections 62, which are arranged on opposite sides of each rib 44 connecting the outer wall 42 and the inner wall 43. The projections 62 are arranged at positions opposing the bottom portion 12C, and the ribs 44 are arranged where interference is avoided with the partition supports 42A and the valve supports 43A. The height of each projection 62 in the direction of the axis L is the same as the height of the inner wall 43 and the outer wall 42 in the direction of the axis L. Each projection 62 is arranged to contact part of the bottom portion 12C. Further, the projections 62 are arranged where interference is avoided with the discharge valve 40 and the gasket 41. In FIG. 10, the projections 62 are arranged at six locations.

The projections 62 further increase the area in which the rear housing 61 contacts the bottom portion 12C. This further suppresses deformation of the bottom portion 12C during compression. Further, the projections 62 are arranged so that there is no interference with the discharge valve 40. Thus, the moving characteristics of the discharge valve 40 are unaffected. The present embodiment also obtains advantages (1) to (8) of the first embodiment.

Third Embodiment

A third embodiment of a compressor will now be described with reference to FIGS. 12 to 14. In this embodiment, the shapes of the front housing 13 and the rear housing 14 are changed from the first embodiment. Otherwise, the structure of the second embodiment is the same as the first embodiment. Like or same reference numerals are given to those components that are the same as the corresponding components of the first embodiment. Such components will not be described in detail.

As shown in FIG. 12, in a front housing 71 of the present embodiment, two ribs 72 connect each pair of partition supports 33A of the outer wall 33 to the corresponding valve support 34A of the inner wall 34. The ribs 72 oppose the bottom portion 11C. Each partition support 33A is located toward the corresponding valve support 34A as viewed from a bolt hole 75. The bolt hole 75 is located along the extension of one of the ribs 72. Each pair of ribs 72 extends from the corresponding pair of partition supports 33A and is connected to the corresponding valve support 34A. The ends of the two ribs 72 in each pair are located near each other in the proximity of the corresponding valve support 34A. Further, as shown in FIG. 13, the height T2 of the ribs 72 in the direction of the axis L is set to be lower than the height T1 of the inner wall 34 and the outer wall 33 in the direction of the axis L. Thus, when the discharge valve 31 and the gasket 32 are held between the cylinder block 11 and the front housing 71, the ribs 72 do not contact the discharge valve 31 and the gasket 32. FIG. 12 shows three pairs of ribs 72 or a total of six ribs 72.

As shown in FIG. 14, in a rear housing 73 of the present embodiment, two ribs 74 connect each pair of partition supports 42A of the outer wall 42 to the corresponding valve support 43A of the inner wall 43. The ribs 74 oppose the bottom portion 12C. Each partition support 42A is located toward the corresponding valve support 43A as viewed from a bolt hole 76. The bolt hole 76 is located along the extension of one of the ribs 74. Each pair of ribs 74 extends from the corresponding pair of partition supports 42A and is connected to the corresponding valve support 43A. The ends of the two ribs 74 in each pair are located near each other in the proximity of the corresponding valve support 43A. Further, although not shown in the drawings, the height of the ribs 74 in the direction of the axis L is set to be lower than the height of the inner wall 43 and the outer wall 42 in the direction of the axis L. Thus, when the discharge valve 40 and the gasket 41 are held between the cylinder block 12 and the rear housing 73, the ribs 74 do not contact the discharge valve 40 and the gasket 41. FIG. 14 shows three pairs of ribs 72 or a total of six ribs 72.

In the front housing 71, each pair of the partition supports 33A is connected to the corresponding valve support 34A by a pair of the ribs 72. This improves the rigidity of the partition supports 33A and the valve supports 34A, and allows for deformation of the bottom portion 11C to be further suppressed during compression. Further, the bolt holes 75 are located along the extensions of the ribs 72. This allows for further improvement in the rigidity of the valve supports 34A. Further, the height T2 of the ribs 72 in the direction of the axis L is set to be lower than the height T1 of the inner wall 34 and the outer wall 33 in the direction of the axis L. Thus, the ribs 72, the discharge valve 31, and the gasket 32 do not interfere with one another, and the moving characteristics of the discharge valve 31 are unaffected.

In the rear housing 73, each pair of the partition supports 42A is connected to the corresponding valve support 43A by a pair of the ribs 74. This improves the rigidity of the partition supports 42A and the valve supports 43A, and allows for deformation of the bottom portion 12C to be further suppressed during compression. Further, the bolt holes 76 are located along the extensions of the ribs 74. This allows for further improvement in the rigidity of the valve supports 43A. Further, the height of the ribs 74 in the direction of the axis L is set to be lower than the height of the inner wall 43 and the outer wall 42 in the direction of the axis L. Thus, the ribs 74, the discharge valve 40, and the gasket 41 do not interfere with one another, and the moving characteristics of the discharge valve 40 are unaffected. The present embodiment also obtains advantages (1), (2), (4) to (6), and (8) of the first embodiment.

It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms.

In the first to third embodiments, the front housing and the rear housing basically have the same structure in which the partition supports extend from the outer wall, and the valve supports are formed by portions of the inner wall. However, the front and rear housings do not have to have the same structure. For example, the above structure may be provided for at least only the rear housing.

In the first to third embodiments, the present invention is applied to a double-headed piston swash plate compressor. Instead, the present invention may be applied to a single-headed piston variable displacement swash plate compressor. Further, instead of rotary valves, discharge and suction mechanisms may be formed by a discharge port and suction port, which are arranged in the partition of the cylinder block, and a reed discharge valve and reed suction valve.

In the first to third embodiment, the present invention is applied to a compressor having three cylinders on one side and a total of six cylinders on the two sides. Instead, the present invention may be applied to a compressor having five cylinders on one side and a total of ten cylinders on the two sides.

In the first to third embodiments, the gasket 32 (gasket 41) is held between the cylinder block 11 (cylinder block 12) and the front housing (rear housing). Instead, as long as the hermetic seal may be ensured, the gasket 32 (gasket 41) may be omitted. In this manner, a gasket is irrelevant to the advantages of the present invention.

The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. 

1. A compressor comprising: a cylinder block including a cylinder bore, wherein the cylinder block includes an end, the end of the cylinder block includes a partition that closes one end of the cylinder bore, the partition includes a bottom portion forming a bottom surface of the cylinder bore, the bottom portion includes a discharge port, and the discharge port extends through the bottom portion and is in communication with the cylinder bore; a housing coupled to the end of the cylinder block, wherein the housing includes an annular outer wall, an annular inner wall located at an inner side of the outer wall, a discharge chamber formed between the outer wall and the inner wall, and a suction chamber formed at an inner side of the inner wall; and a discharge valve held between the cylinder block and the housing, wherein the outer wall includes two partition supports that are in contact with parts of the bottom portion, and the two partition supports are arranged on opposite sides of the discharge valve and extend toward the inner wall.
 2. The compressor according to claim 1, wherein the discharge valve includes a fixed portion, which is held between the cylinder block and the housing, and a valve portion, which is capable of closing the discharge port; the inner wall includes a valve support that holds the fixed portion with the partition; and the valve support is in contact with part of the bottom portion.
 3. The compressor according to claim 1, wherein the housing includes a rib that connects the inner wall and the outer wall, the rib has a lower height than the inner wall and the outer wall, and the rib opposes the bottom portion.
 4. The compressor according to claim 3, wherein the rib is one of two ribs, and the two ribs are respectively extended from the two partition supports toward the inner wall and connected to the inner wall.
 5. The compressor according to claim 2, wherein the housing includes a rib that connects the inner wall and the outer wall, the rib has a lower height than the inner wall and the outer wall, and the rib opposes the bottom portion.
 6. The compressor according to claim 5, wherein the rib is one of two ribs, and the two ribs are respectively extended from the two partition supports toward the inner wall and connected to the inner wall. 